Inkjet print heads usually require some form of fluid purging or priming during their operation and/or their manufacture. Priming can also be useful as a servicing tool by service technicians as well as end users, and also during the printers own self-diagnosis process. Priming is the process of moving ink from the ink reservoir, though the passageways leading to the orifices, and through the orifices. Priming moves the ink into place so that printing can begin. Priming can also be as a print head cleaning mechanism by flushing clean ink through the print head. Over time Inkjet print heads can develop unwanted obstructions in the ink path, the orifices, the nozzle plate or any other area in the pathway the ink travels on its way to the orifices for ejection. Dried out ink is a major cause of obstructions within an Inkjet print head. Obstructions in the ink path usually result in parts of the printed output missing, such as white lines being visible through printed black text.
Printer manufacturers have devised various means for priming an Inkjet print head. Usually the process involves moving the print head to a priming station located at one of the extreme ends of it side-to-side travel. Once docked in the priming station the process of priming begins and involves some method of moving the ink through the print head.